A troubled veteran stalked a high-profile former F.B.I. official at her house in Washington last year — just weeks after the bureau determined he did not pose an imminent threat despite his documented obsession with guns and mass shootings, investigators said.
John C. Perez, 32, an ex-Marine who lives in California, pleaded guilty on Thursday to a federal misdemeanor stalking charge as part of a plea deal that bars him from visiting the Washington area for the next six months, and requires him to attend a half-dozen therapy sessions.
The former F.B.I. lawyer, Lisa Page, who became a persistent target of President Donald J. Trump after her text messages became public in 2017, attended Mr. Perez’s hearing in the Superior Court of the District of Columbia. She asked the judge for more stringent restrictions and accused the bureau of failing to warn her of the possible threat posed by Mr. Perez.
In mid-December, Mr. Perez showed up at least four times at Ms. Page’s house in Washington, making a bizarre claim that she had been witness to his childhood sexual abuse, even though the two had never met, according to a warrant from the Metropolitan Police Department. During one visit, he interacted with Ms. Page’s 11-year-old son.
“The F.B.I. knew about his fixation on me since September, and they said nothing,” Ms. Page said, her voice breaking with emotion and as she stood three feet from Mr. Perez, who remained expressionless. “Three months later, he was on my doorstep.”
A spokeswoman for the bureau did not immediately return a request for comment.
Ms. Page, who worked for the F.B.I. on investigations into Hillary Clinton’s use of a private email server while secretary of state and into possible ties between Russia and Mr. Trump’s campaign, criticized Mr. Trump during his candidacy in text exchanges with another bureau official.
She resigned in May 2018 and became a target of Mr. Trump and his supporters, who claimed that they represented a “deep state” cabal intent on destroying him.
On Thursday, she told the court she had endured “five years of threats by the former president” and his followers, but that nothing had shaken her as deeply as “this event.”
Her emotional appeal roused a rumpled assemblage of public defenders, clerks and people accused of low-level offenses in a heavily trafficked courtroom where plea deals and bench warrants are typically dispatched without fuss or fanfare.
The judge, Robert I. Richter — one of the longest tenured jurists on the federal bench — rested chin on hand and expressed his sympathy with Ms. Page, but did not order any changes to the deal, citing the defendant’s lack of a prior criminal record.
“I don’t know that I disagree with you,” he said. “But it’s hard for me to find better options. It’s not like we can put him away forever.”
Judge Richter then turned to Mr. Perez, a slim man with a rigid military bearing, razor-shaved head and a white dress shirt buttoned to the top. He warned him “to stop this nonsense” and said he would face a long prison sentence if he continued to stalk Ms. Page or did anything to run afoul of the law.
“I’m going to cooperate,” Mr. Perez assured him.
Prosecutors said Mr. Perez traveled cross-country last December with the sole purpose of confronting Ms. Page, after becoming obsessed with her after seeing her on the news.
The court documents do not indicate that Mr. Perez had any political motivations, but rather that he saw Ms. Page as the only person who could provide “closure” in his life.
The Marines discharged Mr. Perez in May 2023 after he made a series of bizarre statements involving Ms. Page that were, upon examination, found to be a symptom of a serious delusional disorder, according to the arrest warrant.
He was barred from Camp Lejeune in North Carolina, where he had been stationed, after military investigators flagged his “erratic behavior,” a desire to obtain weapons, “obsession with mass shootings,” fixation on child sex abuse and the possibility he might engage in workplace violence.
The Marines passed the information along to the F.B.I. around that time. During an interview with agents, Mr. Perez repeated his delusional claims, according to the affidavit.
But they did not take action or notify Ms. Page, she said in court, exercising her right as a crime victim to comment before sentencing.
In February, M.P.D. detectives successfully requested an arrest warrant for Mr. Perez, citing his “persistent and growingly aggressive behavior.”
He complied and flew back to Washington voluntarily.